One method of treating wastewater, such as wastewater from ethanol plants, breweries, pharmaceutical plants, food processing plants, pulp and paper facilities, and the like, is to use an anaerobic treatment reactor. The anaerobic treatment reactor is typically seeded with a population of microorganisms that ingest contaminants in the influent wastewater to form biological flocs or granules (hereinafter “biological flocs”). Wastewater is typically fed into the bottom of the anaerobic treatment reactor and microorganisms consume the waste therein and from biological flocs. After a sufficient startup period, the biological flocs form an anaerobic sludge blanket near the bottom of the anaerobic treatment reactor.
In operation, wastewater is fed into the bottom of the anaerobic treatment reactor and flows upward through the anaerobic sludge blanket bringing the wastewater in contact with the microorganisms that consume the waste therein. The treated wastewater then flows over the weir of the anaerobic treatment reactor as clean effluent.
Conventional anaerobic treatment reactor systems have a limited difference in the specific gravity between the anaerobic sludge blanket and the influent wastewater. Therefore, if the flow rate of the influent wastewater is too high, the limited specific gravity difference can cause the sludge blanket to become diffuse. The result may be an elevated loss of microorganisms over the weir which can result in compromised treatment efficiency and system capacity.